Disappointed with BCM 18" SPR barrel

[lennyo3034]

I posted this on AR-15, but most of them seem to think 3 MOA is perfectly acceptable. I have a new SS410 BCM barrel on a 3 gun rig, and it just isn't shooting up to par. Accuracy with match ammo is 1.5-2.0 MOA and accuracy with FMJ was 2-3 MOA. If I can get 62 grain FMJs down to 1.0-1.5 MOA, I will be satisfied, but is this asking too much for the ammo? Likewise, I have yet to shoot a sub MOA group out of this barrel with match ammo.

Any recommendations on what I should try before I ditch this barrel? What has everyone else's experience been with them? Any ammo in particular it likes/dislikes?

I'm familiar with shooting semi-autos and the follow through necessary for them.

 

[Delta4-3]

My guns will shoot 1.5"ish with ss109' but none are BCM. I don't think that's asking too much.

 

[lennyo3034]

What barrels are you using to get that? I'm in the market now.

 

[Delta4-3]

My SPR, I turned out of a remington 700 5r barrel, my 14.5", and 12.5" I turned from Montana Rifelman blanks, and made my 24" from a Green Mountain Ss blank. I had a White OAk barrel that would do the same. With hand loads the SPR is good for MOA, or a hair above, but it puts several different bullet weights and loads in the same POI. The others shoot considerably better, and are all 1:8" so I run mainly ss109 pulldown for practice, and 75g A-MAX's for wet work. However, they do shoot several loads really well, but not in the same spot. The 24" yields some 0.3" 5 shot groups, but it will put 55g loads and 75g loads in different zip codes.

 

[Delta4-3]

Oh yeah, all are .223 Wylde chamber.

 

[Layton]

I have 2 WOA barrels (16" and 18",.223 wylde)on LRB uppers. Both will do better than that with just about any surplus.

L

 

[K_4c]

How many rounds down the tube? you may need to build up a bearing surface....

I personally would try some 69 or 77 SMK's. Maybe some Hornady 75 bthp's.

 

[jmoney911]

Ouch. Wonder if you just got a bad barrel? My buddy has one of their complete SPR uppers and it shoots MOA without much trouble. Did you try any different ammunition? Can you post a picture of the crown of your barrel?

 

[lennyo3034]

I shot it with:
LC XM855-awful
Winchester Q3315 FBI training rounds- decent 1.5-2.0 MOA
PMC bronze 55 gr- 1.5-2.0 MOA
Handloaded 69 SMK, CCI BR4, varget- 1-1.5 MOA
Prive 75 grain match- 1.5-2.0 MOA

My PSA economy rifle shoots about the same as this. I've tried remounting the barrel nut, different shooter, etc. Today I'm going to test the flash suppressor by removing it and shooting it without one. Otherwise, I'm going to put a DPMS barrel on and see how that does.

Barrel has about 150 rounds down it now.

 

[ORD]

TYPICAL BARFCOM!!

1.5-2MOA with ANY match ammo in that barrel is just unacceptable in my mind (although 2MOA or so with basic ball ammo and the like isn't awful or unheard of), but I can't say I'm surprised in the reaction you received (and likely the circling of the wagons around BCM). I looked into the BCM 18" SPR and 20" SDM/SAM-R barrels for a recent project. When I asked BCM specifically about accuracy guarantees or expectations with match ammo and reloads in a couple different e-mails, particular at extended ranges...CRICKETS! The volume of anecdotal info I came across in my search seemed to report everything from around what you are experiencing to consistent sub-MOA performance with match fodder. To me, that much inconsistency just wasn't acceptable and I wasn't willing to drop $3-400 on something that I wasn't certain would be a performer just to find out for myself where it would actually fall. I also wasn't all that impressed with the general lack of information I got about their "5.56 NATO Match" chamber (which they SAY is the SAM-R chamber), which is supposedly "looser" than a Wylde chamber. If you haven't tried it yet (not sure what "match" ammo you have run so fr to get the 1.5-2MOA...try a variety of different commercial match ammo in it such as FGMM, BH, Corbon, CC, SWA, etc. in weights from 68-77gr and see if it'll group with any of them). You might also let another shooter (or two) have a go at the rifle and see if you get any measurably different results (better or worse). That said...1MOA with any basic military ball ammo that you haven't loaded yourself is pretty unrealistic. If you can get between 2MOA and even down into the 1.5MOA range with 55gr to 62gr ball...call it a day and both you and your rifle have done their part!!

I'd personally ditch the BCM tube and go with a WOA 18" SPR Rifle-length tube or perhaps one of the Rainier Arms Match or UltraMatch 18" SPR tubes. Both are as good as it gets without going to a true custom barrel (and the cost/wait-time associated with one), both are very reasonably priced, and they are proven match-quality barrels with accompanying accuracy, both being sub-MOA capable in the right hands with appropriate ammo. The Rainier tubes are guaranteed to achieve sub-MOA accuracy with match ammo and they both feature a 100% money-back guarantee within 90 days of purchase if you are not satisfied. I have used all of the above barrels I mentioned and they are all excellent.

 

[BCP]

I have a BCM 18" barrel and I can't say enough good things about it. Sounds to me like you might have a dud, or a bad optic/mount perhaps.

 

[Blazin]

Oh yeah, all are .223 Wylde chamber.

I've had real good luck with Wylde chambers too.

Not sure what to tell you Lenny, but I will say I've had better than expected luck with DPMS barrels.

 

[lennyo3034]

BCM has been less than helpful, responding with that they've never had and issue in the past, so it must be the shooter. Criterion, however, was very helpful and offered to take a look at it. I'm looking at a 1-7 twist Douglass barrel at the moment. WOA has a 6 month wait and I'm willing to pay a little more for less of a wait.

Optic is a SS 1-6X24HD mounted on Bobro mount. I will try a DPMS barrel that a friend has.

Blazin, want to give the rifle a shot? See if it's a shooter problem?

 

[MrSunday]

I'm looking at a 1-7 twist Douglass barrel at the moment. WOA has a 6 month wait and I'm willing to pay a little more for less of a wait.

You might want to look at the Compass Lake Douglas SPR barrel with AMU chamber. I had one done by Frank White and it took about 5 weeks. Im very happy with barrel.

Compass Lake Engineering

I would not be happy with the accuracy your getting personally

 

[K_4c]

If you got a line on a Douglass barrel your sitting pretty good! I had a HCS mod 1 and she was a shooter. I recently switch all my AR platforms to KAC products (including a LPR which required about 40-50 rounds before she tightened up).

Sounds like you have no issues doing your own barrel swap so I would proceed with a Douglass or WOA.

best of luck.

 

[ORD]

BCM has been less than helpful, responding with that they've never had and issue in the past, so it must be the shooter. Criterion, however, was very helpful and offered to take a look at it. I'm looking at a 1-7 twist Douglass barrel at the moment. WOA has a 6 month wait and I'm willing to pay a little more for less of a wait.

The guys at Douglas build a hell of an AR barrel (and other barrels in general as well)...I have owned several of their tubes and can attest to that (of course...it always helped being local or at least somewhat local to them...used to be 5 min away, but now its more like 2hrs). They'll take excellent care of you and if you aren't dealing with them directly, many outfits use Douglas blanks to make VERY high end AR barrels, including but not limited to Compass Lake and many others.

As for the WOA barrels, you can find them in stock from time to time at major AR retailers like Rainier Arms and Brownells to name a few who have continuous orders in the pipeline. Fulton Armory is another source for high quality barrels, including Krieger and Criterion, and they generally have some in stock...might be worth a scan of their site to see what's available now.

 

[redneckbmxer24]

Check out the Rainier house brand barrels. Even the cheaper ones are VERY accurate and even come with a 1MOA guarantee. I have also experienced the BCM SS410 barrels not being up to par as far as accuracy.

 

[Blazin]

Blazin, want to give the rifle a shot? See if it's a shooter problem?

Sure thing. I might come to this weekend's HP match, so maybe afterwards.

 

[alan98]

I sold my old bushmaster a year ago and got a BCM mid length 16" upper with the ss 410 match barrel. I also have a Recce style with WOA 16" match barrel. Both rifle ended up with 24.0 Varget and a 77 SMK. Accuracy between the two is not noticeable. 500 yard groups...under MOA...average I'd say 3.5" some a lot less.

Alan

 

[LRRPF52]

I have built several 18" guns using:

18" Compass Lake
18" BCM SS
18" Douglas Select Match from High Caliber Sales
18" LW
18" JP (used)

I also see a lot of these when I run DM Courses, where we shoot out to 600yds with the Mk.262 or 75gr BTHP, and 75gr A-MAX. I think the most accurate pipe I have seen from the bunch so far is the Douglas by HCS, which print sub-MOA groups right off the bat easy. Last one I saw was 1/2 MOA first 3 rounds with Lake City Mk.262 77gr at 2820fps avg.

 

[lennyo3034]

Giving up on the BCM barrel. Will replace it with a spare DPMS to verify that it's actually a barrel issue. Then I will look into a different brand.

 

[Nisils14]

I have a BCM barrel in mine. I'm not very good at shooting and I managed to print .6moa best with a 1.2 avg today while zeroing the rifle, Shooting BH 5.56 77smk. I want to try to get a better shooter behind mine, but I feel pretty confident it'll shoot good.

 

[rchman]

Ball ammo is meant to be minute of man. Anyone claiming that they *consistently* get sub 3 moa with it is most likely full of it. Once upon a time, there was a user of ARFCOM that performed very thorough tests (Collected posts by MOLON). You can review it to see what some of his findings were. Prvi is decent (tested well in his reviews and in my experience can be usually sub moa with my WOA barrel); however, whenever I have accuracy concerns, I go to FGMM.

The groups you mentioned above seem consistent with what I've seen except for the Prvi. FGMM 69gr is where the rifle and ammo begin to outperform my capabilities. Best to date was a hair under .5 MOA in the hands of my brother (5 shots).

If you have a friend with a known good shooting upper, what about getting some FGMM 69gr and swapping uppers for a few rounds?

 

[redirt78]

Lots of good information in this one. Good luck with the swap, hope you figure out where the problem is. Let us know

 

[Delta4-3]

I guess what you're, trying to say is that I'm a liar?

Ball ammo is meant to be minute of man. Anyone claiming that they *consistently* get sub 3 moa with it is most likely full of it. Once upon a time, there was a user of ARFCOM that performed very thorough tests (Collected posts by MOLON). You can review it to see what some of his findings were. Prvi is decent (tested well in his reviews and in my experience can be usually sub moa with my WOA barrel); however, whenever I have accuracy concerns, I go to FGMM.

The groups you mentioned above seem consistent with what I've seen except for the Prvi. FGMM 69gr is where the rifle and ammo begin to outperform my capabilities. Best to date was a hair under .5 MOA in the hands of my brother (5 shots).

If you have a friend with a known good shooting upper, what about getting some FGMM 69gr and swapping uppers for a few rounds?

 

[Danco411]

I have use quite a few different barrels in different builds. The most accurate were the 18" 1:8 Wylde SS LW50 Fluted Lothar Walther made for Spikes. It's a limited run barrel but worth the $380 when they are available at AIM or Primary Arms. The other is the Wilson Combat 1:8 in either the 5.56 NATO 18" or the Wylde 20" SS. Both have been well Sub MOA. As mentioned I have also had good accuracy with WOA and the Ranier tubes. Another good sleeper barrel is the Black Hole 3 grove polygonal in 18". I am taking a chance on the Midway Stoner 18" 1:8 Fluted Wylde they have for $259. I hear they are Douglas blanks chambered for Midway.

 

[lennyo3034]

Just finished the swap. It is now wearing a DPMS 20" barrel. This barrel has shot just under MOA in the past when my friend owned it. If the rifle maintains that accuracy, then I'll know there was something wrong with the BCM barrel. If it still shoots like crap, then I have to look elsewhere, probably optics. Not knowing much about ARs...is it possible something is wrong with the upper receiver? It's an SI-Defense matched billet upper.

 

[Nisils14]

My gunsmith once told me, he came across a PSA upper that would shoot horrible groups. Apparently the barrel was loose in the receiver, customer got a new receiver, and it shot much tighter afterwards.

 

[ORD]

Just finished the swap. It is now wearing a DPMS 20" barrel. This barrel has shot just under MOA in the past when my friend owned it. If the rifle maintains that accuracy, then I'll know there was something wrong with the BCM barrel. If it still shoots like crap, then I have to look elsewhere, probably optics. Not knowing much about ARs...is it possible something is wrong with the upper receiver? It's an SI-Defense matched billet upper.

Having worked with the SI matched upper/lower combinations in the past, I would HIGHLY doubt that it is an issue with either of those components, but hey...stuff happens and it isn't outside the realm of possibility.

If the barrel swap turned out to be a wash, then my first goal is to always rule out the optic/rings/mount. Check for the proper torque of the mount (or rings) to the upper per whichever mfg's components you are using...check that the scope isn't showing any signs of movement in the rings themselves and double-check that the ring cap screws are also torqued down correctly to the recommended values.

From there, unless you bought a bolt that was matched with the BCM barrel or was otherwise checked for proper headspace with the BCM, I'd check that next. While most mil-spec bolts will mate-up/headspace correctly with most quality barrels, you get into issues of stacking tolerances and it is possible that you are either out-of-spec or so far to the extreme ends of it that it is causing your rifle to not shoot up to par.

Good luck in any event!

 

[bustin]

I posted this on AR-15, but most of them seem to think 3 MOA is perfectly acceptable. I have a new SS410 BCM barrel on a 3 gun rig, and it just isn't shooting up to par. Accuracy with match ammo is 1.5-2.0 MOA and accuracy with FMJ was 2-3 MOA. If I can get 62 grain FMJs down to 1.0-1.5 MOA, I will be satisfied, but is this asking too much for the ammo? Likewise, I have yet to shoot a sub MOA group out of this barrel with match ammo.

Any recommendations on what I should try before I ditch this barrel? What has everyone else's experience been with them? Any ammo in particular it likes/dislikes?

I'm familiar with shooting semi-autos and the follow through necessary for them.

You don't really say if you're shooting off a good solid bench with a good scope and good trigger or you are shooting off the tail gate with a red dot sight from Kmart.
That may be one reason you received those kinds of replies on arfcom.
Make sure the scope is solidly mounted on the receiver or a cantilever mount not 1 mount on the receiver and 1 on the hand guard rail...yes I have seen it done.
That being said most fmjs are cheap crap, 62gr SCfmj accuracy is worse than the 55gr fmj. WWB seems to give decent accuracy...good enough for 3 gun.
55gr and 62gr with a small bearing surface allow the bullets to wobble more than a bullet with a long bearing surface like the 69SMKs.
If you reload try 24gr of RE15 with 69gr SMKs loaded as long as will work in your mag. If the barrel wont shoot that load there is something wrong with the barrel.
Several years ago I purchased 11 different brands of 5.56 barrels to test before I started producing barrels. All but 1 of them did not shoot very well. I started checking and found out all of them had muzzle that were swelled 3/4" down in the bore. A .219 inspection pin would slide in 3/4" and then stop. The rest of the bore was .218. After the bullets passed through a .218 bore they would wobble at the end. All of the 55gr ammo shot 3-6" at 100yds but the 69 and 77gr smks would shoot between 1 and 2".
The 1 barrel that was not swelled was a BCM 410 SS. Those barrels are made by Krieger's Criterion division. I talked to Krieger and found out why their muzzles aren't swelled like the rest. That barrel should shoot unless the crown is bad or maybe the barrel is loose...something is up.
Using a Nightforce scope, Geissele trigger, that load of RE15 with 69gr SMKs shooting off a good rest will produce 1/2"groups regularly with a good barrel. It doesn't have to be an expensive barrel just one that is made correctly.

 

[Drifter™]

Those barrels are made by Krieger's Criterion division.

Criterion is no longer associated with Krieger:

Criterion Barrels, Inc.

 

[smschulz]

You don't really say if you're shooting off a good solid bench with a good scope and good trigger or you are shooting off the tail gate with a red dot sight from Kmart.
That may be one reason you received those kinds of replies on arfcom.
Make sure the scope is solidly mounted on the receiver or a cantilever mount not 1 mount on the receiver and 1 on the hand guard rail...yes I have seen it done.
That being said most fmjs are cheap crap, 62gr SCfmj accuracy is worse than the 55gr fmj. WWB seems to give decent accuracy...good enough for 3 gun.
55gr and 62gr with a small bearing surface allow the bullets to wobble more than a bullet with a long bearing surface like the 69SMKs.
If you reload try 24gr of RE15 with 69gr SMKs loaded as long as will work in your mag. If the barrel wont shoot that load there is something wrong with the barrel.
Several years ago I purchased 11 different brands of 5.56 barrels to test before I started producing barrels. All but 1 of them did not shoot very well. I started checking and found out all of them had muzzle that were swelled 3/4" down in the bore. A .219 inspection pin would slide in 3/4" and then stop. The rest of the bore was .218. After the bullets passed through a .218 bore they would wobble at the end. All of the 55gr ammo shot 3-6" at 100yds but the 69 and 77gr smks would shoot between 1 and 2".
The 1 barrel that was not swelled was a BCM 410 SS. Those barrels are made by Krieger's Criterion division. I talked to Krieger and found out why their muzzles aren't swelled like the rest. That barrel should shoot unless the crown is bad or maybe the barrel is loose...something is up.
Using a Nightforce scope, Geissele trigger, that load of RE15 with 69gr SMKs shooting off a good rest will produce 1/2"groups regularly with a good barrel. It doesn't have to be an expensive barrel just one that is made correctly.

All very good and valid observations.
Accuracy is determine by so many variables other than just the barrel.
I see a lot of people "blame" the barrel without fully examining other factors.
Not saying a barrel can't be the problem and not saying it cannot be fixed either ~ lapping, polishing, crowning, etc.
Need to have a consistent set of variables to really determine what is going on ~ trigger, sights, shooter, conditions, ammo, chamber...etc.

 

[lennyo3034]

I've explored all those factors. Now that I've replaced the barrel, I will be able to tell whether it's the barrel or something else.

Shooting was done off a front benchrest and rear bag. Scope is a SWFA SS 1-6x24 HD. I've shot much better groups with irons so the magnification is not an issue. In fact, I really like the scope and feel it did not hinder me in any way. Mount is a bobro and I just checked the bolts, all torqued properly. POI has remained consistent, despite removing the mount multiple times so that tells me it's not a scope or mount issue. Trigger is a Giessele SSA-E. I've shot it without a muzzle device. I've shot it with a different bolt and BCG. I've shot it with a different lower. Not sure where else to look other than the barrel?

 

[bustin]

I've explored all those factors. Now that I've replaced the barrel, I will be able to tell whether it's the barrel or something else.

Shooting was done off a front benchrest and rear bag. Scope is a SWFA SS 1-6x24 HD. I've shot much better groups with irons so the magnification is not an issue. In fact, I really like the scope and feel it did not hinder me in any way. Mount is a bobro and I just checked the bolts, all torqued properly. POI has remained consistent, despite removing the mount multiple times so that tells me it's not a scope or mount issue. Trigger is a Giessele SSA-E. I've shot it without a muzzle device. I've shot it with a different bolt and BCG. I've shot it with a different lower. Not sure where else to look other than the barrel?

Yep, sounds like you have it narrowed down.

 

[bustin]

Criterion is no longer associated with Krieger:

Criterion Barrels, Inc.

And that could be the issue.
If you can slide a .219 inspection pin in the muzzle that could be a problem.
Check the throat with a bore scope, if the lands have been reamed away on one side and not the other that could be a problem.
Look at the crown under 10X or better magnification. If there are burrs off the lands that could be a problem.

 

[lennyo3034]

I shot it with the DPMS barrel, using the same load that the BCM barrel liked the best. Load is 24.5 grains varget under a 69grain SMK.

First the BCM:

Next the DPMS:

Shots in the black were sighters.

Any thoughts? Everything else about the rifle was the same.

 

[Wormydog1724]

I'm pretty happy with my 16" BCM SS410 barrel. With 55 gr FMJ regular ammo it shoots terrible, like 3-4 MOA. But with good ammo, especially v-max's, it's MOA and better.

Loaded some 40 gr V-Max with varget for prairie dogs.

POI shift with the can on

 

[lennyo3034]

BCM got back to me and will take a look at the barrel. Can't really ask for more than that. In the meantime, I've already ordered a Douglas barrel from compass lake.

 

[Jethro21]

I recently bought an upper from Surplus Ammo and Arms, 18" 1/8 Black hole Weaponry polgonal barrel. Took it out to my distance spot and sighted it in at our closest target, 230 yards. 3 rounds to get on target and the next 6 rounds into a nice group just over 2 inches with department issued fodder (American Eagle 55gr). Gotta say I was really impressed with the barrel. Going to try some 77gr Sierra with 2000mr next week, I am certain the barrel will no disappoint. Guess what I am saying is you may take a look at Black hole barrels.

 

[samnev]

I've never had decent groups when using 62 gr ball ammo in any of my AR 15 platform rifles which include, 2 Noveske's Afghan's, POF 415. BCM M4. Colt 6920, Colt 6721, S&W MP 10 Tactical, and SIG 516. groups all were about 3 MOA some larger. With my hand loads all of these rifles are well under 1 MOA for 5 shot 100 yard groups.

 

[lennyo3034]

Here are the results with my last test out of the BCM barrel using FGMM.

About the same as my reloads, I was still hoping for something that could consistently shoot MOA.

I've since ordered a Douglas from Compass Lake and hope to see better results. I just missed out on Bartlein barrels they had in stock.

 

[bustin]

Here are the results with my last test out of the BCM barrel using FGMM.

About the same as my reloads, I was still hoping for something that could consistently shoot MOA.

I've since ordered a Douglas from Compass Lake and hope to see better results. I just missed out on Bartlein barrels they had in stock.

An ARs lock time is much slower than a Rem 700. When you squeeze off hold the trigger to the rear until the bullet contacts paper. At least until you get use to follow through.
Also set up your rear bag so you don't need to pull down on the stock to get on target. If you pull down into the bag the front end(muzzle) will come up when fired. If the muzzle comes up while the bullet is in the bore shots will be erratic.
Some shoot better off a bipod but I think for most it's easier to shoot off a good rest in the front and a good flat bag in the rear so the stock and HG can slide straight back during recoil.

 

[Kilmore]

HCS or Compass Lake 18". Shoot the both with great results. Go with a 1:7 twist stainless and 77OTM. Can't go wrong.

 

[BCP]

Some of those groups look like mine on a bad day. I'll have to grab some targets but I want to say my last outing was about 1.1-1.2MOA average. I've gotten much better groupings though especially with the slower accurate loads like 22.8 H4895 or 24 varget and 69gr nosler.

 

[DesertDenizen]

Lenny, have a friend ot three shoot the rifle and see how consistent all shots are among all shooters.

 

[lennyo3034]

I'm accustomed to shooting precision semi-autos. I prefer shooting a semi-auto off a bipod instead of a benchrest since I can preload the bipod more. On semi-autos, I tend to preload more than with bolt guns because that gives me more consistent follow through. I've had several people shoot the rifle with no better results. I just tested the optic by taking it off it's mount and firing it on a Remington 700. Grouped perfectly so it's not the optic.

I've already ordered a new barrel from Compass lake. 18" Douglas 1-7 Stainless.

 

[2ac]

Your Douglas barrel will not disappoint. The best group out of my Centurion Arms SPR Douglas barrel was about .4, with 24gr Varget and 69 CC.

 

[ashooter]

I'm dragging this thread back to life to see if there's any new info on current production BCM stainless barrels...

I have a new BCM 18" barreled upper that is pretty erratic. I've shot 5 different loads through it and accuracy varies from about 1 moa to about 4 moa. Some 10-15 yr old Black Hills moly'd 75gr blue box shot best at 1 moa or a little better. Asym 75gr and Black Hills Mk262 "seconds" were about 2 moa. Prvi 75gr was about 3 moa. Fed AmEagle 55gr FMJ was a solid 4 moa. With/without muzzle device didn't tighten up groups any, but did change POI. Hell, I've got a couple of "standard" chrome-lined BCM's that'll shoot better than this, so I'm not happy.

My question is: Should I expect this barrel to settle down with some more rounds downrange and tighten up the groups any, or do I just have a finicky barrel?

Thanks

 

[InkedIan]

Check out the Rainier house brand barrels. Even the cheaper ones are VERY accurate and even come with a 1MOA guarantee. I have also experienced the BCM SS410 barrels not being up to par as far as accuracy.

I'm sure it has more to do with the BCM part than the ss410 steel. Both of my criterion ar308 barrels shoot great and are ss410. I doubt you were commenting on the steel itself I just wanted to throw that out there.

I also have an ar15 with a rainer select barrel and I agree with redneck... It shoots great

 

[lennyo3034]

Well since I'm the OP, I might as well give an update. I got rid of the BCM barrel and replaced it with the Douglas. The Douglas is much more accurate, however my chrono data shows it being inconsistent. Standard Deviations vary from 20-30 fps on match ammo. I've only taken it out to 300 yards however, and it rang 2 MOA steel at that distance with boring repeatability.